Plotting H-R Diagrams in R
Astronomy: Exploring Space and Time
University of Arizona
Fall 2018
Created by Tony Gojanovic
What is a H-R Diagram?
The Hertzsprung-Russell diagram, or H-R diagram, is a powerful tool classifying stars in order to understand the nature of stellar evolution. More specifically, from Wikipedia, we have “The Hertzsprung–Russell diagram, abbreviated H–R diagram, HR diagram or HRD, is a scatter plot of stars showing the relationship between the stars’ absolute magnitudes or luminosities versus their stellar classifications or effective temperatures. More simply, it plots each star on a graph measuring the star’s brightness against its temperature (color). It does not map any locations of stars. The related colour–magnitude diagram (CMD) plots the apparent magnitudes of stars against their colour, usually for a cluster so that the stars are all at the same distance. The diagram was created circa 1910 by Ejnar Hertzsprung and Henry Norris Russell and represents a major step towards an understanding of stellar evolution.”
The following H-R diagrams were made using R statistical software and compiled with knitr to create an HTML document.
Hertzsprung-Russell Diagram (Yale Trigonometric Parallax Dataset)
Observational Hertzsprung–Russell diagram
The following Hertzsprung-Russell diagram is based on data found in the R statistical software library GDAData. The data is compiled from the Yale Trigonometric Parallax Dataset and can be found on the webpage of the Astronomy Department of Case Western Reserve University (see references below).
This type of H-R diagram is called an ‘observational Hertzsprung-Russell diagram’ since stars are plotted by color index (B-V) with apparent magnitude on the vertical axis. Another name for this version of the H-R diagram is ‘color magnitude diagram’ or CMD.
Note that the graph colors are not an exact match to star color, but rather just show delineations of different regions.
References
R Implementation: https://rdrr.io/cran/GDAdata/man/HRstars.html.
Simple Interactive H-R Diagram (McDonald Observatory Dataset) for Learning Project
Theoretical Hertzsprung–Russell diagram
The following interactive Hertzsprung-Russell Diagram is based on data obtained from the McDonald Observatory (see reference in this section). This data set and illustration can be used for an observational project since both right ascension and declination has been provided for the majority of stars in the diagram.
This form of the H-R diagram in which apparent magnitude and temperature is called the ‘Theoretical Hertzsprung–Russell Diagram.’ A characteristic of this form of the H–R diagram is that the temperatures are plotted from high temperature to low temperature, which aids in comparing this form of the H–R diagram with the observational form.
Note that the graph colors are not an exact match to star color, but rather just show delineations of different regions.
Spectral Types
The following table shows star names by spectral type and temperature (degrees Kelvin).
| star | O | B | A | F | G | K | M |
|---|---|---|---|---|---|---|---|
| 61 Cygnus A | 4000 | ||||||
| 61 Cygnus B | 4077 | ||||||
| Achernar | 13500 | ||||||
| Aldebaran | 3500 | ||||||
| Alioth | 9520 | ||||||
| Altair | 7700 | ||||||
| Antares | 2700 | ||||||
| Arcturus | 3900 | ||||||
| Barnard’s Star | 2600 | ||||||
| BD +36o2147 | 2700 | ||||||
| BD +43°44 A | 2950 | ||||||
| BD +43°44 B | 2700 | ||||||
| BD +59°1915A | 2650 | ||||||
| BD +59°1915B | 2600 | ||||||
| Betelgeuse | 2700 | ||||||
| Canopus | 6400 | ||||||
| Capella A | 5000 | ||||||
| Capella B | 3200 | ||||||
| Deneb | 9080 | ||||||
| Dubhe | 4750 | ||||||
| epsilon Eridani | 4500 | ||||||
| Fomalhaut | 8720 | ||||||
| HD 224014 | 5200 | ||||||
| Luyten 726-8 A | 2500 | ||||||
| Luyten 726-8 B | 2400 | ||||||
| Luyten 789-6A | 2500 | ||||||
| Luyten 789-6B | 2200 | ||||||
| Merak | 9520 | ||||||
| Polaris | 6400 | ||||||
| Pollux | 4100 | ||||||
| Procyon A | 6500 | ||||||
| Procyon B | 7000 | ||||||
| Regulus | 13000 | ||||||
| Rigel A | 11000 | ||||||
| Ross 128 | 2600 | ||||||
| Ross 154 | 2650 | ||||||
| Ross 248 | 2500 | ||||||
| Sirius A | 9500 | ||||||
| Sirius B | 28000 | ||||||
| Spica | 19500 | ||||||
| Sun | 5770 | ||||||
| Vega | 9700 | ||||||
| Wolf 359 | 2400 | ||||||
| ZZ Ceti | 10300 | ||||||
| α Centauri A | 5800 | ||||||
| α Centauri B | 4000 | ||||||
| α Centauri C | 2600 | ||||||
| α Crusis A | 19500 | ||||||
| α Crusis B | 16500 | ||||||
| β Centauri | 20000 | ||||||
| β Crusis | 29000 | ||||||
| ε Indi | 4000 |
.
Star Positions by Constellation
The following table provides the star names along with apparent and absolute magnitude, temperature, constellation, right ascension and declination along with a few notes. If you’re using this to locate the stars, verify positions with a reliable star map. Not all star positions were located.
| constellation | star | apparent | absolute | temp | spectral_type | RA | Dec | notes |
|---|---|---|---|---|---|---|---|---|
| Andromeda | ||||||||
| Andromeda | Ross 248 | 12.30 | 14.70 | 2500 | M | 23h 41m 55.0361s | +44° 10′ 38.825″ | Red dwarf flare star |
| Aquarius | ||||||||
| Aquarius | Luyten 789-6A | 12.30 | 14.90 | 2500 | M | 22h 38m 33.73s | –15° 17′ 57.3″ | Red dwarf; part of a triple star system |
| Aquarius | Luyten 789-6B | 12.30 | 15.90 | 2200 | M | 22h 38m 33.73s | –15° 17′ 57.3″ | Red dwarf; part of a triple star system |
| Aquila | ||||||||
| Aquila | Altair | 0.80 | 2.20 | 7700 | A | 19h 50m 46.99855s | +08° 52′ 05.9563″ | Type A main sequence; oblate shape |
| Auriga | ||||||||
| Auriga | Capella A | 0.10 | -0.70 | 5000 | G | 05h 16m 41.35871s | +45° 59′ 52.7693″ | Yellow giant; binary (part of quad system) |
| Auriga | Capella B | 0.10 | 9.50 | 3200 | M | 05h 16m 41.35871s | +45° 59′ 52.7693″ | Yellow giant; binary (part of quad system) |
| Bootes | ||||||||
| Bootes | Arcturus | -0.10 | -0.30 | 3900 | K | 14h 15m 39.7s | +19° 10′ 56″ | Red giant |
| Canis Major | ||||||||
| Canis Major | Sirius B | 8.40 | 8.40 | 28000 | B | 06h 45m 09.0s | −16° 43′ 06″ | Faint white dwarf companion |
| Canis Major | Sirius A | -1.40 | 1.40 | 9500 | A | 06h 45m 08.917s | −16° 42′ 58.02″ | White main sequence star;binary |
| Canis Minor | ||||||||
| Canis Minor | Procyon B | 10.70 | 13.00 | 7000 | F | 07h 39m 18.11950s | +05° 13′ 29.9552″ | White dwarf companion |
| Canis Minor | Procyon A | 0.40 | 2.70 | 6500 | F | 07h 39m 18.11950s | +05° 13′ 29.9552″ | Binary system star |
| Carina | ||||||||
| Carina | Canopus | -0.60 | -3.10 | 6400 | F | 06h 23m 57.10988s | −52° 41′ 44.3810″ | Bright white giant |
| Cassiopeia | ||||||||
| Cassiopeia | HD 224014 | 4.50 | -9.50 | 5200 | G | 23h 54m 23.0s | +57° 29′ 58″ | Yellow hypergiant; rho cassiopeiae |
| Centaurus | ||||||||
| Centaurus | β Centauri | 0.60 | -4.10 | 20000 | B | 14h 03m 49.40535s | –60° 22′ 22.9266″ | Triple star system |
| Centaurus | α Centauri A | 0.00 | 4.40 | 5800 | G | 14h 39m 36.49400s | –60° 50′ 02.3737″ | Yellow main sequence |
| Centaurus | α Centauri B | 1.40 | 5.80 | 4000 | K | 14h 39m 35.06311s | –60° 50′ 15.0992″ | Orange main sequence |
| Centaurus | α Centauri C | 11.00 | 15.80 | 2600 | M | 14h 39m 35.06311s | –60° 50′ 15.0992″ | Red dwarf |
| Cetus | ||||||||
| Cetus | ZZ Ceti | 14.10 | 12.30 | 10300 | B | 01h 36m 13.60s | −11° 20′ 32.2″ | Variable white dwarf |
| Cetus | Luyten 726-8 A | 12.60 | 15.40 | 2500 | M | 01h 39m 01.54s | –17° 57′ 01.8″ | Red dwarf flare star |
| Cetus | Luyten 726-8 B | 13.00 | 15.80 | 2400 | M | 01h 39m 01.54s | –17° 57′ 01.8″ | Companion star |
| Crux | ||||||||
| Crux | β Crusis | 1.30 | -4.00 | 29000 | O | 12h 47m 43.26877s | –59° 41′ 19.5792″ | Binary system star |
| Crux | α Crusis A | 0.90 | -4.00 | 19500 | B | 12h 26m 35.89522s | −63° 05′ 56.7343″ | B-type star; multipe star system |
| Crux | α Crusis B | 0.90 | -3.50 | 16500 | B | 12h 26m 35.89522s | −63° 05′ 56.7343″ | B-type star; multipe star system |
| Cygnus | ||||||||
| Cygnus | Deneb | 1.30 | -7.50 | 9080 | A | 20h 41m 25.9s | +45° 16′ 49″ | Blue white supergiant |
| Cygnus | 61 Cygnus B | 6.05 | 8.33 | 4077 | K | 21h 06m 55.31s | +38° 44′ 31.4″ | Binary k dwarf |
| Cygnus | 61 Cygnus A | 5.20 | 7.50 | 4000 | K | 21h 06m 53.9434s | +38° 44′ 57.898″ | Binary k dwarf |
| Eridanus | ||||||||
| Eridanus | Achernar | 0.50 | -1.00 | 13500 | B | 01h 37m 42.84548s | –57° 14′ 12.3101″ | Main sequence binary system |
| Eridanus | epsilon Eridani | 3.70 | 6.10 | 4500 | K | 03h 32m 55.84496s | −09° 27′ 29.7312″ | less than 1 billion years old |
| Gemini | ||||||||
| Gemini | Pollux | 1.20 | 0.80 | 4100 | K | 07h 45m 18.94987s | +28° 01′ 34.3160″ | Evolved orange giant; exoplanet Pollux b |
| Indus | ||||||||
| Indus | ε Indi | 4.70 | 7.00 | 4000 | K | 22h 03m 21.658s | −56° 47′ 09.52″ | Main sequence and two brown dwarfs; exoplanet |
| Leo | ||||||||
| Leo | Regulus | 1.40 | -0.60 | 13000 | B | 10h 08m 22.311s | +11° 58′ 01.95″ | Blue white; binary system |
| Leo | Wolf 359 | 13.50 | 16.80 | 2400 | M | 10h 56m 28.99s | +07° 00′ 52.0″ | Red dwarf flare star |
| Lyra | ||||||||
| Lyra | Vega | 0.00 | 0.50 | 9700 | A | 18h 36m 56.33635s | +38° 47′ 01.2802″ | Main sequence; pole star in 13, 727 |
| Ophiuchus | ||||||||
| Ophiuchus | Barnard’s Star | 9.50 | 13.20 | 2600 | M | 17h 57m 48.49803s | +04° 41′ 36.2072″ | Low mass red dwarf |
| Orion | ||||||||
| Orion | Rigel A | 0.20 | -6.80 | 11000 | B | 05h 14m 32.27210s | −08° 12′ 05.8981″ | Blue white supergiant; multiple star system |
| Orion | Betelgeuse | 0.50 | -5.50 | 2700 | M | 05h 55m 10.30536s | +07° 24′ 25.4304″ | Red supergiant |
| Piscis austrinus | ||||||||
| Piscis Austrinus | Fomalhaut | 1.20 | 1.60 | 8720 | A | 22h 57m 39.0465s | −29° 37′ 20.050″ | Tripple system star; K type main sequence |
| Sagittarius | ||||||||
| Sagittarius | Ross 154 | 10.40 | 13.30 | 2650 | M | 18h 49m 49.36216s | –23° 50′ 10.4291″ | Red dwarf flare star |
| Scorpius | ||||||||
| Scorpius | Antares | 1.00 | -4.50 | 2700 | M | 16h 29m 24.45970s | −26° 25′ 55.2094″ | Red supergiant |
| Taurus | ||||||||
| Taurus | Aldebaran | 0.90 | -0.20 | 3500 | M | 04h 35m 55.23907s | +16° 30′ 33.4885″ | Orange giant star |
| Ursa Major | ||||||||
| Ursa Major | Alioth | 1.80 | -0.20 | 9520 | A | 12h 54m 01.74959s | +55° 57′ 35.3627″ | A1p “peculiar” |
| Ursa Major | Merak | 2.30 | 0.40 | 9520 | A | 11h 01m 50.47654s | +56° 22′ 56.7339″ | Main sequence |
| Ursa Major | Dubhe | 1.80 | -1.30 | 4750 | K | 11h 03m 43.67152s | +61° 45′ 03.7249″ | Giant binary |
| Ursa Minor | ||||||||
| Ursa Minor | Polaris | 2.00 | -4.10 | 6400 | F | 02h 31m 49.09s | +89° 15′ 50.8″ | Yellow supergiant; pole star |
| Ursa Minor | BD +36o2147 | 7.50 | 10.50 | 2700 | M | 11h 03m 20.19400s | +35° 58′ 11.5682″ | Red dwarf variable |
| Virgo | ||||||||
| Virgo | Spica | 1.00 | -3.60 | 19500 | B | 13h 25m 11.579s | −11° 09′ 40.75″ | Blue giant; binary |
| Virgo | Ross 128 | 11.10 | 13.50 | 2600 | M | 11h 47m 44.3974s | +00° 48′ 16.395″ | Red dwarf flare star |
| Unclassified | ||||||||
| Sun | -26.80 | 4.80 | 5770 | G | G type main sequence | |||
| BD +43°44 A | 8.10 | 10.30 | 2950 | M | ||||
| BD +43°44 B | 11.10 | 13.20 | 2700 | M | ||||
| BD +59°1915A | 8.90 | 11.10 | 2650 | M | ||||
| BD +59°1915B | 9.70 | 11.90 | 2600 | M | ||||
.
References
Hemenway, Mary Kay and Brad Armosky, “H-R Diagram,” The University of Texas at Austin McDonald Observatory, 2001. Website: https://mcdonaldobservatory.org/sites/default/files/pdfs/teachers/hrd.pdf
Star right ascension, declination and notes were compiled from Wikipedia.